If everyone in the UK drove at 70mph max we would reduce CO2 emissions by 1 million tonnes a year!

You could save 4p a mile, that’s worth Â£200 per year.

You will stop 20% sooner, that’s 20 metres less.

You will emit 40g less CO2 per mile, that’s 200,000g per year.

I think single-issue campaigns can be pretty powerful if they are well-designed and catch on. 70max seems to live up to this idea.

It’s also quite smart in terms of its pledge mechanism – you get a free sticker for your car and there’s a Flickr group to upload a snap of it to. (How about ones for my bike? And what about the emissions from those post-office trucks that deliver it? Eh? – okay I’m being picky.)

Also good to see is the level of referencing for the calculations so it’s grounded in some decent facts and figures.